Without limiting the scope of the invention, its background is described in connection with fasteners.
One such fastener is taught in U.S. Pat. No. 8,845,256, issued to Gaw, entitled, “Fastener and Fastener Assembly with Discontinuous Threadform”. This inventor is said to teach a fastener comprising a cylindrical shaft, a head attached to the shaft, and two or more external longitudinal threadforms, where each threadform comprises a plurality of spaced protrusions forming a separate sinusoidal path around the shaft. When the shaft is inserted into a corresponding mating receptacle, a combination of the shaft and the mating receptacle provides two or more pitches. The disclosure is said to further provide for a fastener assembly.
Another such fastener is taught in U.S. Patent Publication No. 2013/0117997, filed by Ehinger, et al., and entitled “System and Method for Installing a Fastener Rod”. These inventors teach a system and method for installing a fastener rod that includes a fastener rod starter apparatus that includes a first end for engaging a fastener rod, a second end for insertion into an insertion hole, and an elongated body of closed cell foam having sufficiently low density and high compressibility to displace fluid in the insertion hole and be compressed to allow installation of the fastener rod into the insertion hole. A method for installing a fastener rod may also include lubricating an insertion hole with a fluid and inserting a starter element into the insertion hole. The starter element may have sufficiently low density and high compressibility to displace the fluid in the insertion hole and be compressed by the fastener rod inserted into the insertion hole.